quick question to do with my tachometer gauge
 

i put the proper dizzy in my cAR plugged it in started car up and the rpm gauge went all haywire its not accurate at all. the idle is perfect the needle is moving all over what causes this to happen so i know how to fix it?

check the wiring

ya it loose wiring to the icm im pretty sure.. so.

problem fixed it was the icm ignitor control module.